New problem - water pump noise

Hi everyone - I'm back (not that I ever left) with a new problem.

When I bought my car I noticed a grinding noise coming from the engine every once in a while, replaced my supercharger coupler, got rid of most of the noise, but still had a grinding (barely noticeable, but definitely there). Sometimes it can be felt through the brake pedal and sometimes it can't. Sometimes there's grinding, sometimes not. Now, here's why I think it's the alternator.

First I should mention this noise can only be heard/felt in drive/gear. Basically below 800 RPM. I did the famous 'put your ear on the end of a screwdriver' listening test. Sorry for the lack of a creative name   . Anywho, I checked various spots on the engine for this grinding noise and came up with nothing at first. I checked the block in as many places as I could reach, both heads, valve covers, supercharger, LIM, transmission, etc. Nothing. I checked as many pulleys as i could, no pulley noise. Until I came to the alternator. I put my screwdriver end on the end of the alternator closest to the belt, and I heard the grinding and the screwdriver actually vibrated my head! I checked the bracket it's attached to, and a similar but less-so feeling/noise.

Bad alternator bearings or whatever is inside there? The battery seems to get charged fine. If you've been following my other post, sometimes when my engine idle gets funny my lights dim a little. Anyone have any ideas??

Thanks!

-Andrew Z

i dont get the noise but i am getting the "dim light syndrome" most all the time now. im interested in the answer too

Rebuild or replace the Alternator.
BTW, The screw driver trick is a stethoscope.
Especially before the winter, when you are going to start using the items that put a heavy load on it.
Such as: the rear window defogger, mirror heat, seat heat, etc,
Napa has a reman unit for reasonable money that puts out 150 Amps as opposed to the stock one putting out 140 amps.
Every little bit helps. IIRC it was lees than $200.00
Or if you are into rebuilding your own you can get the all parts needed for our Alternator = AC Delco CS 144 from www.alternatorparts.com or you can buy an Alternator direct from them with an increased output.
Do not buy the one with an external regulator if you have a Supercharged engine as it will not fit.
Also, do what i just did recently and add a #4 gauge cable from the Alternator output terminal to the underhood connector that feeds the Battery.
The OEM cable is surprisingly undersized. I just added the new cable, which I made myself and piggy backed the original. Bought approx. 4 feet of #4 Battery cable from the auto parts store with a 5/16" and 3/8" terminal ends and crimped them on myself.
This does not increase the voltage but allows the Amperage an easier path to the Battery.
To increase voltage by about one volt, you need to add the resistor in the sense line at the Alternator per previous write-ups on here.

After your engine is warmed up, place your hand on the blower, then on the alternator. If the alternator is warmer than the blower, it's going bad. On an engine that's been running for 30 mins, an alternator with bad bearings will be too hot to touch.

A long time ago, I heard a siren-like wine from under the hood, sounded a bit like blower wine. My mechanic tested the alternator using above method, and declared it was bad. Still under warranty, I took to the dealership - they confirmed the diagnosis, replaced at no charge.

So just to clarify, the grinding noise I am hearing is likely the alternator, seeing what the screwdriver test proved? I'll test the temperatures tomorrow with my hand when I go to leave work. The engine will be cold when I'm getting ready to leave.

I guess I could always do a VERY VERY short 'remove the belt' test too. I'll try the others first though. Thanks guys...I'll let you know what I find.

It is most likely the bearing(s) going bad in the Alternator.
Have heard it many times.
Re-Read my post, Ive added additional info.
Good luck with whatever direction you take.

Thanks again Rick. You've been a huge help in all my car issues thus far haha. Much appreciated!

I wouldn't say the screw driver test proves it 100%, but it gives good direction, as you've indicated from your test. Have you ever loosened or removed your alternator for any reason? Check that the bolts and brackets are still tight. The one thing you said about it only making noise when in gear doesn't line up with a failing alternator, though.

If you feel lots of heat from the alternator, then you have two tests corroborating your theory. Then, and only then, would I replace the alternator. Your idea for belt-removal test won't tell you a whole lot, because all of the the pulleys will stop moving (obviously no noise), but if you can slip off the belt with engine off, you might try turning the alternator pulley by hand to see if it feels wobbly or rough. Should be smooth with little play on a good alternator. Good luck!

I agree w/alternator; I replaced 2 of them for the same reason (noise). First time, I suspected I spun a bearing - local mechanic just listened to the car run and said "alternator." He was right... Second time, it squeaked real bad. All you need to do is slip the belt off at the tensioner, then turn the alt pulley by hand. If you get any grinding, your bearnigs are probly shot. IMHO htey shoulda used bigger bearings in the alt snout, given the constant pull of the tensioner.

I replaced my second bad alt with a OE alternator from gmpartsdirect.com - only problem, which was not serious, was that they gave me one with a damaged pulley. Used a cheapie air wrench and fat screwdriver (to hold the fan still) to get it off & swap them. Bought tohe alt from GM because I learned good things about their remanufacturing line for their alternators. The remans may well be better than the new ones.

Albertj

Quote :

The remans may well be better than the new ones.

In my experience, this seems correct. My OEM alternator failed at 30k miles. The replacement, installed by GM dealer, has lasted 164k miles since that time.

man my alt is 14 years old. thats got to be a record

AA - I see what youre saying about how it might not be the alternator because of the test not being 100%, but remember I mentioned it only happens around 700 ish RPMs. With a few experiences I've had with other pulleys on various engines, that was the case. The noise would go away after a certain RPM. I'm cautious in the diagnosis, but pretty positive at this point what it is. That being said, I HAVE had it off recently but this has been doing the noise since about 3 months ago, slowly getting worse. I'll still check the mounting bolts and then check the play in the pulley and try the belt-off test. Thanks again everyone!

Wow, robotennis, you bought your car brand new?

nope. but I'm certain that it is the original.
no record from the previous owner that its been changed.but i don't know for sure. what i do know is it was completely original when i got it.

robotennis61 wrote:

man my alt is 14 years old. thats got to be a record

I also am running the original alternator on mine. It has a small amount of noise coming from it, but still is working good.
btw I also have the dimming light syndrome at idle.

woggy wrote:

robotennis61 wrote:

man my alt is 14 years old. thats got to be a record

I also am running the original alternator on mine. It has a small amount of noise coming from it, but still is working good.
btw I also have the dimming light syndrome at idle.

dimming lights at idle most likely weak or undercharged battery. I would take it to a repair place to check:

- CCAs (how many cold cranking amps does the battery put out
- alternator output (is it making the rated output)

I suspect you will find the battery is weak. The alternator may or may not be weak. Many autozones and walmarts now have the battery for our Rivs.



Albertj

If you bring it somewhere for the free tests, have them load test the battery to it's rated CCA, as Albert mentioned.
Assuming the Battery that is installed is the correct one for the vehicle.
The CCA is a critical parameter for our cars due to the amount of current draw from the various systems.
They can also put a carbon pile load test on the alternator and check if it is putting out it's rated 140 amps.at some speed above idle.
I added the extra battery cable from the alternator to the power point under the hood and think I have solved some problems I was having with current draw at low RPM's.
Without a carbon Pile Tester, I can't be absolutely sure though.
Seat of the pants is telling me that it helped. My HVAC fan doesn't slow down at idle in gear any more. My turn signals don't flash slower at idle, etc.
I am still only reading 13.8 to 14.1 volts at idle in gear.
The next thing I want to do is add the diode to the battery thermistor circuit and trick it to put out about 0.6 more Volt.
If that doesn't work, then I will put an overdrive pulley on the alternator. I know it will reduce the life of the alternator somewhat but I don't care. I'll just replace brushes more frequently.

Quote :

If that doesn't work, then I will put an overdrive pulley on the alternator. I know it will reduce the life of the alternator somewhat but I don't care. I'll just replace brushes more frequently.

If an alternator turns out to be the problem, it's actually not that bad, as the alternator is fairly inexpensive, and takes what, 45 minutes to install?

Beats hunting down elusive electrical problems, imo.

I did the 'temperature' test today and found the alternator to be a little htoter than the supercharger. I'll take the belt off when I have a minute to check out the alternator via 'handspin'. I'll check back when I do that. Thanks again everyone.

woggy wrote:

robotennis61 wrote:

man my alt is 14 years old. thats got to be a record

I also am running the original alternator on mine. It has a small amount of noise coming from it, but still is working good.
btw I also have the dimming light syndrome at idle.

Mine is original too! I was thinkin about changing it, but haven't had any charging or noise issues. How long can these things go for?

BMD wrote:

woggy wrote:

robotennis61 wrote:

man my alt is 14 years old. thats got to be a record

I also am running the original alternator on mine. It has a small amount of noise coming from it, but still is working good.
btw I also have the dimming light syndrome at idle.

Mine is original too! I was thinkin about changing it, but haven't had any charging or noise issues. How long can these things go for?

With parts such as an alternators I subscribe to the " if it ain't broke, dont fix it " theory.

Bert

ibmoses wrote:

With parts such as an alternators I subscribe to the " if it ain't broke, dont fix it " theory.

Bert

This is the right approach with an alternator. Unless you are having a problem, or looking for an upgrade, don't bother. And the Riv's original alternator really doesn't need upgrading until you've got some major equipment added.

Derek,
How is your Alternator doing since overhaul.?
Any problems at idle.?

wow! good info. i replaced my stock battery with a optima red top with 800 CCA that should be good right?

Will be looking at the alternator tomorrow. I have too much to do inside tonight and I worked overtime 5 hours today lol. Updates tomorrow.